The United Nations Human Rights Council has delayed by six months the release of a report into alleged war crimes committed during Sri Lanka's civil war, following request by the country's newly-elected government for more time to conclude its internal probe.

The report, which was earlier scheduled to be released on March 25 during the 28th session of the UN Human Rights Council, will now be out in September this year.

UN High Commissioner for Human Rights Zeid Ra'ad Al Hussein said it was a "difficult decision" to postpone the release of the report but added that given the changing context in Sri Lanka, there is possibility that important new information may emerge which will strengthen the report. "This has been a difficult decision," Zeid said.

"There are good arguments for sticking to the original timetable, and there are also strong arguments for deferring the report's consideration a bit longer, given the changing context in Sri Lanka, and the possibility that important new information may emerge which will strengthen the report," he said.

He sought to assure that the deferral was "for one time only", and guaranteed that the report would be published by September. "There should be no misunderstanding," Zeid said.

Image: A demonstrator holds a placard during a protest against Sri Lanka for alleged war crimes. Photograph: Reuters